1. Field of the Invention
The present invention relates to wiring configurations for semiconductor components suitable for high-frequency electronic units such as television tuners.
2. Description of the Related Art
A wiring configuration for a known semiconductor component will now be described with reference to FIGS. 5 and 6. FIG. 5 is a plan view of a semiconductor component according to the wiring configuration for the known semiconductor component, and FIG. 6 is a plan view of principal parts of a circuit board according to the wiring configuration for the known semiconductor component. As shown in FIG. 5, a semiconductor component 51 includes a main body 52 and a plurality of terminals 53 provided for the main body 52.
The terminals 53 include a plurality of signal terminals 53a, a plurality of ground terminals 53b, and a plurality of unused terminals 53c. The unused terminals 53c are unnecessary terminals for connection to electrical circuits existing in various other high-frequency electronic units.
As shown in FIG. 6, a circuit board 54 includes a wiring pattern 55. The wiring pattern 55 includes first traces 56 for signals having first lands 56a corresponding to the signal terminals 53a, second traces 57 for grounding having second lands 57a corresponding to the ground terminals 53b, and island-shaped third lands 58a corresponding to the unused terminals 53c. 
The semiconductor component 51 is connected to the circuit board 54 by soldering the signal terminals 53a, the ground terminals 53b, and the unused terminals 53c to the first lands 56a, the second lands 57a, and the third lands 58a, respectively. In this manner, the wiring configuration for the known semiconductor component is realized (see, for example, Japanese Unexamined Patent Application Publication No. 2001-177040).
When the electrical circuit of this semiconductor component 51 is broken, the semiconductor component 51 is removed from the circuit board 54 by heating the solder that connects the semiconductor component 51 to the circuit board 54, and then a new semiconductor component 51 is soldered to the circuit board 54.
However, according to the wiring configuration for the known semiconductor component, the areas of the island-shaped third lands 58a to which the unused terminals 53c are soldered are small, and the third lands 58a can be easily accidentally removed from the circuit board 54 when the semiconductor component 51 is removed for exchange, resulting in a large number of defective circuit boards 54. Moreover, since the first traces 56 and the second traces 57 are arranged so as to avoid the island-shaped third lands 58a, the efficiency with which space is used becomes low, and furthermore, the widths of the lines are reduced. Thus, transmission lines in, in particular, high-frequency circuits become susceptible to noise.